CBD – growth of an industry beyond the science?
Dr Simon Steenson
CBD (short for cannabidiol) is everywhere at the moment, from CBD oils to its use as an ingredient in sweets and cakes, in drinks including beer, waters and cappuccinos, and even in houmous!
A recent YouGov consumer survey estimated that 11% of UK adults had tried a CBD product (around 6 million people), with higher consumption in younger adults (15% in 25-34 vs. 8% in over 65 year-olds) and females (13% vs. 9% in males). The CBD market in Europe is worth around £253 million, larger than the markets for vitamin C and vitamin D supplements combined. CBD certainly seems to be one of the fastest growing wellbeing trends for 2019.
But, what exactly is CBD and is it legal?
CBD is extracted from ‘hemp’ varieties of the cannabis plant, typically grown for fibre. These cannabis types have a low content of the psychoactive compound THC (delta-9 tetrahydrocannabinol) and a higher amount of CBD, which does not produce the characteristic ‘high’ experienced from the THC in cannabis. In fact, CBD is not classed as a controlled substance in the UK and is legal, provided the THC content is less than 0.2%.
However, since January 2019, the EU has categorised CBD added to foods or sold as a supplement as a ‘novel food’, which means products need to be evaluated and authorised before they are permitted to be placed on the market. Only one application has been submitted so far, for the use of CBD in food supplements for adults (with a daily intake of up to 130 mg), excluding pregnant and lactating women. Therefore, strictly speaking, at the moment CBD food products and supplements are classed as an unauthorised ‘novel food’, although the UK Food Standards Agency is committed to finding ‘a proportionate way forward to achieve compliance in the marketplace.’
Does CBD have any health benefits?
CBD in medical conditions
Cannabis-based medicines containing CBD have been developed for the treatment of specific medical conditions. Sativex (nabiximols) is a mouth spray containing extracts of THC and CBD (in equal amounts), prescribed for the treatment of multiple sclerosis (MS)-related spasticity, and is the first to be licensed in the UK (approved in 2010). Epidiolex, a highly purified CBD liquid, already approved in the US in 2018 is currently going through the UK licensing system for the treatment of seizures in children with two rare forms of epilepsy.
There is also an interest in the clinical use of CBD for medical conditions such as schizophrenia, cancer and Parkinson’s disease, but the evidence for these uses is largely at the pre-clinical stage (cell culture and animal studies) and data from large-scale human trials are not available.
These important and serious medical uses are in contrast to the populist ‘wellbeing’ claims for CBD, including improving mood or helping with sleep, where evidence is lacking.
CBD for anxiety, pain and sleep
Only a few small human studies have reported positive results for anxiety, pain and sleep:
- For example, in a double-blind randomised study looking at anxiety relief, healthy male volunteers received oral CBD at doses of 150 mg (n=15), 300 mg (n=15), 600 mg (n=12) or placebo (n=15), before a simulated public speaking test. Compared to placebo, pre-treatment with 300 mg of CBD significantly reduced anxiety during the speech, but no significant differences in anxiety scores were observed between groups receiving CBD at 150 mg or 600 mg, or placebo.
- For pain relief, only a single randomised controlled study has demonstrated an effect of CBD, but this included a very small sample of patients with neurological conditions, such as MS.
- Although it has been widely suggested that CBD can help with sleep disturbances, the findings to date from human studies are very limited and inconclusive.
Larger, well-conducted clinical trials, with market relevant doses (i.e. amounts typically found in the products on sale), are needed to confirm if CBD offers any real benefit.
What if I would like to try a CBD product?
While scientific interest in CBD is increasing, the evidence so far from human trials is very limited, and it is too soon to know whether CBD in the small amounts provided by oils, capsules, food and drink products may offer a real therapeutic benefit. The scientific evidence does not support many of the unsubstantiated and non-evidence based uses of CBD, and it should not be used as a substitute for prescribed medical treatments.
The evidence for the supposed benefits of CBD in commercially available products is largely anecdotal. Users have reported that it works for them, whether it is to feel more relaxed or get a better night’s sleep. The World Health Organization has concluded that CBD is generally safe and well tolerated, but some side effects, such as dry mouth, diarrhoea and fatigue, have been reported in human studies.
If you are thinking about trying CBD, it is better to buy from a reputable retailer. However, these products tend to only contain very small amounts of CBD, and there is still no guarantee these products will be of good quality or contain CBD at the dose listed on the label. Importantly, speak to your GP if you have a medical condition or are taking any medication, before giving it a try.
If you are interested in reading more on the regulatory aspects of CBD products, what is known about its physiological effects, safety, and the evidence from human trials about its potential health effects, why not read our Facts Behind the Headlines article in Nutrition Bulletin, Cannabidiol: A budding industry!
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